The human ankle consists of three bones, the tibia, the fibula, and the talus, which are bound to the bones of the foot and to one another by ligaments. The particular arrangement of the three bones allows the foot to rotate about three orthogonal axes relative to the leg. The ligaments place elastic limits on the extent of such rotation or movement.
Many ankle injuries occur when ankle movement exceeds the elastic limit of one or more ligaments. One relatively common ankle injury, known as eversion of the ankle, results when the ankle moves too far outward as the foot rolls over. Another relatively common ankle injury, known as inversion of the ankle, results when the ankle moves too far inward as the foot rolls over. Many individuals, and athletes in particular, require external support for their ankles as a result of previous eversion or inversion injuries or ongoing concerns about adequately protecting their ankles.
A common practice among athletes is to tightly wrap the ankles with medical adhesive tape. Although "taping" is generally recognized as an effective way to protect a weak or injured ankle, it suffers several drawbacks, as well. For example, an effective tape job necessarily restricts movement of the foot in all directions relative to the leg, thereby limiting desirable ankle motions as well as undesirable ones. Taping is also relatively costly because the tape is typically used only once, and it often requires a trainer to be properly applied.
Fabric ankle wraps are sometimes used as an alternative to taping. The fabric wraps may be used more than once, but their elasticity and lack of adhesiveness renders them less effective than medical adhesive tape in terms of immobilizing the joint.
A variety of relatively rigid support structures have been designed as alternatives to medical tape and fabric wraps. However, those skilled in the art continue to seek improvements in areas such as reliable support, user comfort, user mobility, application simplicity, and/or manufacturing cost.